"This study provides some of the first evidence of an association
between a particular cognitively stimulating activity, in this
case, speaking multiple languages on a daily basis, and brain
function," John Woodard, an aging expert from Wayne State
University, who was not involved with the study, said in a
statement.

To test the idea in an aging population, Brian Gold and his
colleagues at the University of Kentucky College of Medicine
scanned the brains of 30 healthy bilingual and monolingual adults
ages 60 to 68. They used functional magnetic resonance imaging
(fMRI), which shows blood flow to brain regions in real time. An
increase in blood flow to a specific brain region signals that
region is likely becoming more active.

While their brains were being scanned, participants completed a
task to measure their cognitive flexibility called a color-shape
task-switching game. The participants were shown one of two
possible shapes (square or circle) in one of two colors (red or
blue) at the center of a screen. In some instances participants
had to name the color of the flashed image, in others the shape,
and in others the task switched back and forth from participants
needing to indicate color to shape.

Both groups performed the task accurately, though bilingual
individuals were faster than monolinguals. Even so, the brain
scans suggested bilingual participants expended less energy in
the brain's frontal cortex thought to be involved in such task
switching, the researchers said.

"This suggests that bilingual seniors use their brains more
efficiently than monolingual seniors," Gold said in a statement.

To find out when this cognitive benefit from bilingualism kicked
in, the researchers ran the same experiment on younger
participants with an average age of 31. As expected, younger
adults were faster than older ones at completing the task.
However, bilingual younger adults did no better than monolingual
individuals on the task.

"Together, these results suggest that lifelong bilingualism may
exert its strongest benefits on the functioning of frontal brain
regions in aging."

In fact, another study showed the
brains of bilingual adults functioned better and for longer
after individuals developed Alzheimer's disease; the bilinguals
were also diagnosed with the disease about four years later, on
average, than those who spoke just one language.

Past research has suggested
bilingualism can benefit even infants, with one study showing
bilingual 7-month-olds more quickly adapted to different learning
cues than babies from single-language households. (The
"bilingual" babies were spoken to in two languages by parents.)
And Janet Werker, a psychologist at Vancouver's University of
British Columbia, has found
learning two languages can confer babies with cognitive
advantages, such as special auditory and visual sensitivity.

The new research on aging and bilingualism was funded by the
National Institutes of Health and the National Science
Foundation.